Finally this Saturday it was confirmed that the outbreak of bilateral pneumonia of unknown origin, happened in the sanatorium medical light from the city of San Miguel de Tucuman which has already caused six deaths and 19 infections, is the result of a bacterium called legionella pneumophilawhich causes legionellosis disease. This was confirmed by the analyzes of the samples sent to the National Administration of Laboratories and Health Institutes (Anlis) “Dr. Carlos Malbran to confirm the etiology of the outbreak.
“It’s a bacterium called legionella pneumophila which was first described in the 1970s as the cause of an outbreak of pneumonia. Generally, it is associated with stagnant water and the generation of aerosols”, she indicated to THE NATION Mary Martha Greco (MN 112235), head of the Infectious Disease Service at the Spanish Hospital of La Plata.
The director of Epidemiology of the Municipality of San Isidro, Bárbara Broese (MN 130018), pointed out that there are two ways in which the disease can develop: “A pneumonic form that is known as the ‘legionnaire’s disease’which is treated with antibiotics for 7 to 10 days, and another that is known as the ‘Pontiac’s disease’which is like a flu syndrome that heals itself, without antibiotics, in 3 to 5 days”.
For the clinical doctor of the Italian Hospital, Luis Camera (MN 51995), the disease is contracted by the contamination of water that is drunk in tanks or by microdroplets of aerosols and steam from freshwater mirrors, such as lakes or lagoons, in bathrooms with Jacuzzi, showers or fountains.
According to the doctor Damian Eagle (MN 12625), member of the executive committee of the Argentine Society of Infectious Diseases (SADI)person-to-person transmission “is considered an exceptional event.”
“The sources of aerosols that have been related to the transmission of the legionella They include cooling towers for air conditioning, hot and cold water systems, humidifiers and whirlpool installations,” Broese said, adding that “car and home air conditioning systems do not use water to cool the air; therefore, they do not present a risk.”
The mortality rate by legionellosis depends, according to the specialist, on the severity of the disease, the suitability of the initial antimicrobial treatment, the environment in which the infection was contracted and various factors related to the host, depending on whether it has any previous health condition . “In untreated immunosuppressed patients, the mortality rate can be between 40% and 80%, although it can be reduced between 5% and 30% through appropriate case management, and depending on the severity of the disease. clinical signs and symptoms. In general terms, the mortality rate ranges between 5% and 10%”Broese noted.
Regarding the development of the disease, Greco specified that “it has a incubation period of two to 10 days and generally the most serious complication is progressive pneumonia that leads to respiratory failure and can lead to multi-organ failure”.
Broese agreed and added that if not treated the pneumonic form, usually, worsens in the first week. “As with other risk factors that cause severe pneumonia, the most frequent complications of legionellosis are respiratory failure, shock, and acute and multi-organ kidney failure,” the specialist determined. And she added that healing, which always requires antibiotic treatment, “is usually complete, although it may require several weeks or months. In rare cases, severe progressive pneumonia or ineffective treatment can lead to brain sequelae.”
Aguila explained that one of the main control measures is any action that “minimizes the proliferation of this bacterium in the water distribution and storage systems, in the refrigeration and aerosol generation systems.” Furthermore, he cited the World Health Organization (WHO) and made a series of recommendations: